Helmut Thielicke, Encounter With Spurgeon (Fortress, 1963):

It is evidence of the substance and also of the excellence of form in Spurgeon’s sermons that — removed from the situation in which they were originally preached, and also from the magnetism of Spurgeon’s personality! — they lose very little in print. Not for a moment do they give the impression that we are reading merely historical testimonies to which we no longer have any immediate access and which come alive only in the act of reinterpretation. Even for us they are still a bubbling spring whose water needs no filtering or treatment. And I venture to ask: Of what other preacher of the nineteenth century could this be said? …

But this bush from old London still burns and shows no signs of being consumed. Here Christians dare to speak of miracle. (pp 3-4)

Later:

I am almost tempted to shout out to those who are serving the eternal Word as preachers, and to those who are preparing to do so, in what I hope will be productive hyperbole: Sell all that you have and buy Spurgeon (even if you have to grub through the second-hand bookstores). (p 45)

Thankfully that’s not necessary. Many of Spurgeon’s works can be read online for free. And his massive sermon manuscript archive is still in print thanks to the folks at Pilgrim Publications. We are blessed to have such easy access to his publishing legacy.